| Author | Message | ||
     Brian Vogel Grand Master Username: guyslp Post Number: 1359 Registered: 6-2009 |
I hate posting this, since I seem to recall having asked, "What is this thing?," regarding the same item on LRK37110, but I simply cannot find the post.  Obviously it's a diode, but what kind and what's its role? Are replacements still available? My question comes about based upon the thread, EGR electrical system trouble, on rollsroyceforums.com. I was hoping I could point the questioner to the thread I seem to remember, but cannot find. I know that a couple of our regulars here also participate there, too, and could possibly answer there directly. As the recent thread on the green resistor on the hydraulic reservoir shows, it never hurts to have a repeat question on an obscure part that also includes pictures, so I thought I'd ask again. | ||
| Robert Noel Reddington Frequent User Username: bob_uk Post Number: 71 Registered: 5-2015 |
EGR is not fitted to my car. So I won't have this part. As you know a diode is a one way valve for electricity. The usual reason for the diode in this case is to stop the electricity going the wrong way and feeding back to another device. To test simple use ohm meter one polarity wont show a reading and other polarity will show more a less 0 ohms. Another use for diodes is that if connected the wrong way round and enough voltage applied the diode will breakdown and conduct. This can be used as voltage regulator. Like a zenner diode. I should think that this diode if not available from Lucas will be available else where. Tandy? If its being used as a one way valve then the choice of diodes will be big. If it's voltage regulation then the choice will be narrower. Usually voltage reg diodes are heat sink mounted. Which is the finned thing under the headlight on later Triumph motorbikes. | ||
| Robert Noel Reddington Frequent User Username: bob_uk Post Number: 72 Registered: 5-2015 |
Forgot Diodes are a simple single junction which like half a two junction transitor. Diodes are very reliable. The photo is good and shows clean terminals. Still worth a quick check in situ as is will be fine Battery turned off. | ||
| Robert Noel Reddington Frequent User Username: bob_uk Post Number: 76 Registered: 5-2015 |
I have just made a mistake. If the diode is tested in situ as is because other stuff is in the circuit erroneous readings on the not conducting polarity may result making it appear the diode is faulty. So disconnect the spade terminal. Note that like points condensers that were ok until the wire fell off. Diodes are like this as well. It was ok until the mechanic broke it sort of thing. So unless there's a fault in the egr I would leave well alone. |
